The sound of silence: reducing impact noise.Many of today's apartments have carpet--even in kitchens and bathrooms. More than fashion, wall-to-wall carpeting, and its underlay, often is relied on to reduce the transmission of sounds--especially impact sounds--between floors. Without some kind of cushion on concrete surfaces, the sounds of pounding feet and moving furniture can travel freely between floors, resulting in unacceptably high levels of thumping, thudding thud
1. A dull sound, as that of a heavy object striking a solid surface.
2. A blow or fall causing such a sound.
intr.v. thud·ded, thud·ding, thuds
To make a heavy, dull sound. and pitter-patter of what acoustical engineers call structure-borne sound.
As carpets give way to easy-to-clean hard-surface flooring in the face of recurring re·cur
intr.v. re·curred, re·cur·ring, re·curs
1. To happen, come up, or show up again or repeatedly.
2. To return to one's attention or memory.
3. To return in thought or discourse. media images of magnified dust mites dust mite House dust mite, see there , apartment owners can find themselves with a problem: How to enjoy the allergy reducing benefits of hardwood, laminate laminate,
n a thin slice of porcelain or plastic fabricated in a dental lab, which is cemented to the front of the teeth to cover gaps, whiten stained teeth, or reshape chipped or broken teeth. of ceramic tiles while meeting the technical requirements for impact sound resistance? It's not enough to simply rip out Verb 1. rip out - burst out with a violent or profane utterance; "ripped out a vicious oath"; "ripped out with an oath"
burst out - give sudden release to an expression; "We burst out laughing"; "'I hate you,' she burst out" carpet and put down the hard-surface flooring of choice. In fact, that is a guaranteed mute to trouble. To understand why, an apartment owner must know something about how impact sound is transmitted and measured.
The movement of non-impact or airborne sounds, such as speech, music and household noise, that travel through walls and ceilings is measured on a scale called the Sound Transmission Class (STC STC Supplemental Type Certificate (FAA)
STC Society for Technical Communication
STC Subject to Change
STC Surf the Channel (website)
STC Sound Transmission Class
STC Singapore Turf Club ). Currently, a minimum rating of 50 STC is required by code between adjoining residential units, although this is not always achieved in the real world. Even when minimum requirements are achieved, many people living with 50 STC between themselves and neighbors consider it an inadequate barrier. But because the physics of impact sounds from fooffall and furniture movements are different from the noises of non-impact sounds, another scale has been developed to measure what acoustical engineers refer to as impact sound.
Impact Insulation Class (IIC See infranet. ) measures the transmission of sound waves caused by an object or objects striking a surface--such as a foot hitting the floor--and transmitting the sound through the material. There is a minimum code rating of 50 IIC for residential applications. This IIC rating is now mandatory where it was once optional. Luxury and premium apartment communities require ratings even higher than 50.
Impact Insulation Class becomes the measurement scale of choice when dealing with sounds created as building parts resonate res·o·nate
v. res·o·nat·ed, res·o·nat·ing, res·o·nates
1. To exhibit or produce resonance or resonant effects.
2. from the impact of movement and the shifting of loads. Think of the floor on an apartment as a big, concrete drum skin, with the folks below living under that drum. Renters are then at the mercy of the drum thumpers above. That is why everyone in stacked housing situations should be protected from structure borne noise.
Considering installing hardwood floors in an apartment? Installing it directly on an 8-inch concrete floor might be easy, but it would be a mistake. Wood-on-concrete offers little impact sound insulation, and a sure source of suffering for renters living below. In fact, no hard-surface flooring can be installed over concrete floors alone while still meeting isolation requirements.
While some of the impact sound wave is absorbed by the floor assembly, what appears on the other side of the structure is what we call "noise." Traditional impact insulation products, such as cork sheets, paperboard and synthetic sheet materials, have been around for years; however, nothing matches the impact insulating value of a relative newcomer to sound insulation--recycled rubber.
Made from post-consumer waste Post-consumer waste is a waste type produced by the end consumer of a material stream; that is, where the waste-producing use did not involve the production of another product. , more than 35 million pounds of old tires are converted each year into rubber mats of various thicknesses to be used for impact sound insulation. Rubber, with its natural resiliency and ability to absorb vibrations, provides excellent properties for the attenuation Loss of signal power in a transmission.
The reduction in level of a transmitted quantity as a function of a parameter, usually distance. It is applied mainly to acoustic or electromagnetic waves and is expressed as the ratio of power densities. of impact sound. A rubber mat has a higher IIC rating per unit of thickness than alternative materials, and its very firm consistency allows easy installation of new flooring directly over the mat's surface. A 3/16-inch rubber mat between hardwood flooring and 8 inches of concrete produces a 59 IIC. Similar ratings can be achieved with ceramic tiles or vinyl floor surfaces over a variety of commonly used floor assemblies.
While today's society is noisy, sound control need not be the problem it once was for renters. New understanding and innovations in sound reduction have produced products that have impact sound under control. And that's good news for urban planners List of urban planners chronological by initial year of plan.
Paul Downey P. Eng P. ENG Professional Engineer
P. ENG process engineer ., is an engineer with Dodge-Regupol Inc. He can be reached at email@example.com or 416/440-1094 Photos courtesy of Dodge-Regupol.